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Ghost shark -

Ghost sharks, or chimaeras, are some of the oldest species of fish in the world, diverging from true sharks around 400 million years ago. That makes them just as old, if not older, than trees and forests. Today, chimaeras stick to the darkest and murkiest depths of the ocean.

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Frilled Shark -

The ancient and intimidating frilled shark is at least 150 million years old, meaning it swam the oceans at the same time some of the Jurassic period's most famous dinosaurs, such as the stegosaurus, still roamed the Earth. Today, frilled sharks lurk in the deepest depths of the ocean, far from any human activity.

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Komodo dragon -

One of the most famous remnants of an ancient, reptilian Earth, is the Komodo dragon of Indonesia. Today, they are the largest lizards on Earth, and have been around for nearly four million years.

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Echidna -

The platypus's close relative, which looks like a cross between a porcupine and a hedgehog, is at least 110 million years old, making it the oldest surviving species of mammal in the world. Native to Oceania, they are the only mammal that lays eggs besides the platypus.

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Musk oxen -

Native to the upper regions of North America, musk oxen have been around for nearly 200,000 years, making them nearly as old as modern humans. 

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Shoebill stork -

The shoebill stork is a huge bird with a strikingly unique profile. The massive beaks of these birds help them hunt larger prey than most of their stork and waterbird relatives. The descendants of shoebills are from the same group of animals as the tyrannosaurus rex, but they broke off from their common ancestor around 65 million years ago. 

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Alligator gar -

Alligator gars have remained virtually unchanged by evolution for the past 100 million years, since the early Cretaceous period. Apparently, no change has been necessary, as they have been a thriving species for all of that time, and even today are in no danger of extinction or endangerment.

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Vicuña -

Once considered holy by the Incan Empire of South America, vicuñas are the still-living ancestors of modern llamas. Vicuñas have roamed the lowlands and highlands of Patagonia for at least 130,000 years.

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Chambered nautilus -

One of the most ancient inhabitants of Earth that is still with us is the chambered nautilus, a seafaring cephalopod that has been around for 500 million years. That's twice as old as the oldest species of dinosaurs!

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Tapir -

The earliest evidence of tapirs come from the Miocene, around 23 million years ago. These large and ancient mammals, distant relatives to horses, could once be found on every continent in the world, Antarctica excluded, but now are mostly found in Central America, South America, and Malaysia.

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Southern white rhinoceros -

While they may look as though they'd be right at home roaming the Earth amongst the dinosaurs, rhinoceroses are actually mammals with very little relation to the massive reptiles of 65 million years ago. That doesn't mean, however, that these magnificent creatures aren't ancient in their own right; the white rhinoceros has inhabited Southern Africa for at least 14 million years.

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Wobbegong shark -

The fascinatingly unique wobbegong shark got its start in the Upper Jurassic period, around 145 million years ago. This means that they, along with many other aquatic forms of life, survived the mass extinction event that wiped out the dinosaurs 65 million years ago. The elusive nature of the wobbegong, and its expertly utilized camouflage, has helped it thrive well into the present without any threat of endangerment. 

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Babirusa -

Babirusa are distinct from other hogs, and animals in general, in that their tusks, meant for protection and combat, will eventually grow backwards to the point of piercing their own skull and killing them. It's incredible that such a poorly designed animal could last so long, but there are depictions of Babirusas in some of Southeast Asia's oldest cave paintings.

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Horseshoe crab -

Famously, yet inaccurately, labeled the world's oldest living fossil, the horseshoe crab is an arthropod at least 450 million years old, making it older, and far more resilient, than the dinosaurs.

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Tuatara -

These tiny reptilians, today found only in New Zealand, may look like shrunken down dinosaurs. And they essentially are! Tuataras are the last surviving members of the family of reptiles that first appeared in the Triassic period around 250 million years ago. It's likely only due to their small size that tuataras survived the mass extinction event 65 million years ago that wiped out their dinosaur cousins.

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Chinese giant salamander -

The largest species of salamander on Earth, the Chinese giant salamander is a living remnant of the ancient world of the Jurassic period, first appearing around 170 million years ago. Regularly exceeding six feet (1.8 meters) in length, the giant salamander population has dipped dangerously close to extinction in the 21st century due to climate change and habitat loss.

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Lake sturgeon -

Sturgeon are another incomprehensibly ancient species of fish that have managed to stick around for more than 100 million years. Sturgeon, although far smaller in numbers now than they were in the Cretaceous period, can still be found in the Great Lakes of North America, and can grow up to 12 feet (3.5 meters) in length.

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Okapi -

While concrete and undisputed fossil records are hard to come by when it comes to the history of the okapi, it is generally accepted that they are in the running for the title of the oldest large mammals on Earth. Native to Central Africa, the okapi, sometimes referred to as a "zebra giraffe," has roamed the Earth for at least 18 million years.

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Red panda -

One of the cutest and cuddliest creatures in the world, the red panda is actually of no relation to the panda bear. They are part of a unique family of animals, of which they are the only surviving member. Red pandas have been lounging around the forested mountains of Nepal and China for an estimated 25 million years, based on fossil records.

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Caribou -

Caribou, or reindeer, have roamed the snowy lands within the Arctic Circle since somewhere around two million years ago and were one of the first sources of meat encountered by early humans when they crossed the Bering land bridge 16,000 years ago.

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Siberian musk deer -

These small musk deer, native to the northernmost regions of China and eastern Russia, first appear in fossil records during the Middle Pleistocene around one million years ago.

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Lice -

One of they primary sources of embarrassment in so many children's lives, lice have an admittedly solid survival strategy that has worked for the species for nearly 130 million years.

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Brachiopods -

Brachiopods are some of the oldest and, at one time, most populous invertebrates on the planet. According to the available fossil records, brachiopods first appeared over 500 million years ago, and shortly after became the most common shelled creature in the sea. They remained dominant until the Permian mass extinction, which occurred around 250 million years ago. While they managed to hold on, brachiopods have yet to return to their former glory.

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Coelacanth -

The coelacanth fish has truly made the comeback of the epoch. With the earliest fossils of a coelacanth dating back more than 400 million years ago, these ancient fish were thought to have gone extinct during the late Cretaceous period, around 66 million years ago. That is until, in 1938, scientists discovered that the coelacanth had survived in seclusion the entire time.

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Bactrian camel -

While there are hardly more than 1,000 Bactrian camels left on Earth, they have proven to be one of the most resilient animals on Earth for the past two million years. Equipped for any condition, Bactrian camels can thrive in the hottest deserts and through the harshest winters.

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Horsetails -

Horsetail plants are considered living fossils, as they have gone through little to no evolutionary change for their entire existence. Horsetails can be found nearly everywhere in the world, excluding most of Oceania and all of Antarctica. They first appeared in the early Jurassic period, around 200 million years ago.

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Cow sharks -

It's no secret that sharks are some of the oldest fish in the ocean, but cow sharks are especially old and have remained virtually unchanged for their entire existence, which stretches nearly 200 million years. Unlike most modern sharks, cow sharks have seven gill slits on each side of their body, a characteristic shared with the most ancient progenitors of sharks.

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Lamprey -

Certainly one of the most unnerving creatures in the sea, lampreys are also some of the oldest. These primitive, bloodsucking fish have been around for at least 360 million years, according to the available fossil evidence.

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Jellyfish -

The oldest multi-organ creatures to exist are still thriving in the depths of the ocean today. As of 2007, the oldest jellyfish fossils discovered date to over 505 million years ago. Some scientists speculate that they may have existed as early as 700 million years ago.

Source: (Far and Wide) (Mom.com) (Smithsonian Magazine)

See also: Prehistoric animals you won't believe existed

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